brooks (kb46587) - HW 6- Newton's Laws of Motion - bybee - (24141)
3
1. Sup=Ss
This print-out should have 15 questions.
Multiple-choice questions may continue on
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before answering.
001
10.0 points
Two men decide to use their cars to pull a
truck stuck in mud. They attach ropes and
one pulls with a force of 813 N at an angle
of 29° with respect to the direction in which
the truck is headed, while the other car pulls
with a force of 1113 N at an angle of 21° with
respect to the same direction.
813 N
121°
1113 N
What is the net forward force exerted on
the truck in the direction it is headed?
Answer in units of N.
29⁰°
002 10.0 points
Consider a man standing on a scale which
is placed in an elevator. When the elevator is
stationary, the scale reading is S..
Scale
Find Sup the scale reading when the el-
evator is moving upward with acceleration
1
a=93, in terms of S..
2. Sup
3. Sup
5. Sup
=
4. Sup =
=
8. Sup
=
7. Sup =
=
10 | 2009 | 10
ا
=
+D
6. Sup=Ss
9176
Ss
7
c
Ss
9. Sup
10. Sup = 0 m/s²
003 (part 1 of 3) 10.0 points
A dragster and driver together have mass
942.2 kg. The dragster, starting from rest,
attains a speed of 25.5 m/s in 0.56 s.
Find the average acceleration of the drag-
ster during this time interval.
Answer in units of m/s².
004 (part 2 of 3) 10.0 points
What is the size of the average force on the
dragster during this time interval?
Answer in units of N.
005 (part 3 of 3) 10.0 points
Assume the driver has a mass of 71.5 kg.
What horizontal force does the seat exert
on the driver?
Answer in units of N.
006 10.0 points
Robert de Niro pushes down the length of the
handle of a 13.8 kg lawn spreader. The handle
makes an angle of 43.1° with the horizontal.
Robert wishes to accelerate the spreader from
rest to 1.38 m/s in 1.5 s.
What force must Robert apply to the han-
dle?/nbrooks (kh46587) - HW 6- Newton's Laws of Motion - hybee - (24141)
013 10.0 points
The distance between two telephone poles is
51 m. When a 1.3 kg bird lands on the
telephone wire midway between the poles, the
wire sags 0.188 m.
The acceleration of gravity is 9.8 m/s².
How much tension in the wire does the bird
produce? Ignore the weight of the wire.
Answer in units of N.
Answer in units of N.
007 10.0 points
Two forces are the only forces acting on a
2.1 kg object which moves with an accelera-
tion of 3.3 m/s² in the positive y direction.
One of the forces acts in the positive z direc-
tion and has a magnitude of 9.9 N.
What is the magnitude of the other force
$₂?
Answer in units of N.
008 10.0 points
A(n) 1330.7 kg car is coasting along a level
road at 37.3 m/s. A constant braking force
is applied, such that the car is stopped in a
distance of 73.3 m.
What is the magnitude of the braking force?
Answer in units of N.
009 (part 1 of 4) 10.0 points
The instruments attached to a weather bal-
loon have a mass of 5.9 kg. The balloon is
released and exerts an upward force of 110 N
on the instruments.
The acceleration of gravity is 9.8 m/s².
What is the acceleration of the balloon and
the instruments?
Answer in units of m/s².
010 (part 2 of 4) 10.0 points
After the balloon has accelerated for 8.2 s, the
instruments are released.
What is the velocity of the instruments at
the moment of their release?
Answer in units of m/s.
011 (part 3 of 4) 10.0 points
Assume: The upward direction is positive.
What net force acts on the instruments
after their release?
Answer in units of N.
012 (part 4 of 4) 10.0 points
How long after their release does the direc-
tion of their velocity first become downward
(negative)?
Answer in units of s.
014 (part 1 of 2) 10.0 points
The knot at the junction is in equilibrium
under the influence of four forces acting on
it. The F force acts from above on the left at
an angle of a with the horizontal. The 5.3 N
force acts from above on the right at an angle
of 46° with the horizontal. The 5.3 N force
acts from below on the right at an angle of
40° with the horizontal. The 5.7 N force acts
from below on the left at an angle of 50° with
the horizontal.
46°
40°
5.3 N
5.3 N
(knot)
5.7 N
50°
Note: F, a are not to scale.
What is the magnitude of the force F?
Answer in units of N.
015 (part 2 of 2) 10.0 points
What is the angle a of the force F as shown
in the figure above?
Answer in units of º.
